SYNTHETIC WEBBING FOR SLINGS

Transcription

1 RECOMMENDED STANDARD SPECIFICATION FOR SYNTHETIC WEBBING FOR SLINGS WSTDA-WB WEB SLING & TIE DOWN ASSOCIATION, INC. $25.00

2 Web Sling & Tie Down Association. All rights reserved. No part of this publication may be produced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of theweb Sling &Tie Down Association.This publication is circulated subject to the condition that it shall not, by way of trade or otherwise, be lent, sold, hired out or otherwise circulated withoutwstda's prior consent.

3 FOREWORD This Recommended Standard Specification applies to class 5 and class 7 synthetic webbing used in the manufacturing of synthetic web slings. This standard recommends construction, identification and marking of class 5 and class 7 synthetic webbing. The exclusion from this Recommended Standard Specification of synthetic sling webbing of different synthetic materials and capacities is not intended to preclude their use and shall not be interpreted in this manner. Synthetic sling webbing made from materials or construction other than those detailed in this Recommended Standard Specification shall be used in accordance with the recommendations of the webbing manufacturer, sling fabricator or qualified person. The specifications contained in this Recommended Standard Specification for Synthetic Webbing for Slings were formulated under the auspices of the Web Sling & Tie Down Association, Inc. This Recommended Standard Specification is intended to assist manufacturers of webbing and web slings, to serve as a guide to the industry involved in the manufacture of synthetic sling webbing, and to serve as a guide to governmental and other regulatory bodies responsible for the selection of webbing used in synthetic slings. Safety is the paramount consideration involved in the use of any synthetic webbing for sling purposes. This standard does not purport to address all safety concerns, if any, associated with the use of synthetic webbing or slings. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of the regulatory limitations prior to use. The appropriate synthetic webbing shall be selected by the user for their specific applications. Users shall be knowledgeable about federal, state, provincial, local, and industry regulations applicable to synthetic web slings constructed of class 5 and class 7 synthetic sling webbing. Figures shown in this Standard are for illustration only and are not intended to represent usage, design or manufacturing processes. MANDATORY AND ADVISORY RULES Mandatory rules are characterized by the use of the word shall. If a rule is of an advisory nature, it is indicated by the use of the word should, or it is stated as a recommendation. WEB SLING & TIE DOWN ASSOCIATION, INC. 9 Newport Drive, Suite 200 Forest Hill, Maryland Phone (443) Fax (443) wstda@stringfellowgroup.net Website: First Published and Copyright 2005 First Revision 2015

4 Contents Chapter 1.0 TERMINOLOGY & DEFINITIONS OF SYNTHETIC SLING WEBBING Section 1.1 Section 1.2 Section 1.3 Purpose... 1 Description... 1 Definition of Terms Chapter 2.0 CONSTRUCTION AND IDENTIFICATION OF SYNTHETIC SLING WEBBING Section 2.1 Section 2.2 Section 2.3 Section 2.4 Purpose... 3 Materials... 3 Construction... 3 Treatments... 4 Chapter 3.0 STANDARD PROCEDURES FOR TESTING SYNTHETIC SLING WEBBING Section 3.1 Section 3.2 Section 3.3 Section 3.4 Purpose... 4 Types of Tests... 4 Test Procedures... 4 Certification... 5 Chapter 4.0 RECOMMENDED OPERATING PRACTICES Section 4.1 Section 4.2 Section 4.3 Section 4.4 Section 4.5 Purpose... 5 Environmental Considerations... 5 Inspection... 5 Inspection Records... 5 Repair of Webbing... 5

5 CHAPTER 1.0 TERMINOLOGY AND DEFINITIONS OF SYNTHETIC SLING WEBBING SECTION 1.1 PURPOSE SECTION 1.2 DESCRIPTION This chapter provides a description and definitions that apply to nylon and polyester synthetic sling webbing used as the primary material for synthetic web slings. Synthetic sling webbing is a high-tenacity narrow fabric closely woven in a variety of weaves and principally used for slings that have to withstand a tensile stress of: Class pounds per inch of width ( kilograms per millimeter of width) Class pounds per inch of width (175 kilograms per millimeter of width) SECTION 1.3 DEFINITION OF TERMS ABRASION The mechanical wearing of the webbing surface resulting from frictional contact with other materials or objects. BINDER Yarn that is used to hold the two plies together in the sling webbing. BREAKING STRENGTH The maximum load that a material can withstand while being stretched or pulled before failing or breaking (also know as tensile strength). CATCH CORD Yarn used to lock and prevent raveling of the weft yarn on shuttle-less weaving machinery. DENIER A numbering system which expresses the weight in grams of a multi filament yarn that is 9000 meters in length. Lower numbers represent finer sizes of filament yarn, and higher numbers represent coarser sizes of filament yarn. ELONGATION The measurement of webbing stretch expressed as a percentage of the original unloaded webbing length at a given applied load. DYED (WEBBING) dyes. A process of coloring fibers, yarns or fabrics with either natural or synthetic FILLING The yarn running from selvedge to selvedge perpendicular to the warp. Also referred to as weft and/or picks. 1

6 SECTION 1.3 DEFINITION OF TERMS (con t) HIGH TENACITY Higher than normal breaking strength with a range of 6.0 to 9.5 grams per denier as compared to regular tenacity of lower than 6.0 grams per denier. MULTIFILAMENT A yarn consisting of many continuous filaments or strands, as opposed to a monofilament, which is one strand. NATURAL (WEBBING) A fabric that has not gone through the dying process. Can be webbing directly off the loom (loom state) or that has undergone a heat setting process without dye or subsequent chemicals. NEEDLE LOOM insertion. A weaving machine in which a needle, rather than a shuttle, is used for weft PICKS The yarn running from selvedge to selvedge perpendicular to the warp. Also referred to as weft and/or filling. RAVELING The process of undoing or separating the weave or knit of a fabric. SELVEDGE / SELVAGE The narrow edge of woven fabric that runs parallel to the warp. SHUTTLE LOOM A weaving machine having a boat-shaped device usually made of wood with a metal tip that carries filling yarns through the shed in the weaving process. STUFFER A longitudinal load bearing yarn in webbing. Yarns running in the warp direction through a woven fabric to increase the fabric's strength and weight. SURFACE PLIES Exterior or outside plies of a plied weave, sometimes referred to as face or back ply of the weave. SYNTHETIC FIBER Man-made manufactured fibers. SYSTEM 3 AND SYSTEM 5 to reduce raveling. Specific weaving techniques woven into the edge of the webbing TREATED WEBBING Webbing to which a chemical treatment has been applied which offers some degree of protection against an environmental or mechanical hazard. UNTREATED WEBBING Webbing without any additional chemical treatment. WARP The set of yarn in all woven fabrics that run lengthwise and parallel to the selvedge and is interwoven with the filling. WEBBING Fabric that is closely woven in a variety of constructions or patterns. WEFT The yarn running from selvedge to selvedge perpendicular to the warp. Also referred to as picks and/or filling. WOVEN Refers to a fabric composed of at least two sets of yarns, warp and filling, which is then formed by weaving. It is the interlacing of these sets of yarns. YARN A continuous strand of textile fibers or filaments in a form suitable for knitting, weaving or otherwise intertwining to form a textile fabric. 2

7 SECTION 2.1 PURPOSE SECTION 2.2 MATERIALS CHAPTER 2.0 CONSTRUCTION OF SYNTHETIC SLING WEBBING This chapter provides an outline of materials, construction characteristics and identification of nylon and polyester class 5 and class 7 synthetic sling webbing, and identification of the synthetic sling webbing manufacturer. Webbing shall be woven from a synthetic yarn that is heat and light resistant Yarns may be twisted or flat (not twisted) and composed of commercially available deniers. Nylon yarn used in the manufacturing of sling webbing shall be high tenacity, continuous multifilament Polyester yarn used in the manufacturing of sling webbing shall be high tenacity, continuous multifilament. SECTION 2.3 CONSTRUCTION Webbing shall be certifiable to tensile strength, and have uniform thickness and width Typically sling webbings are constructed as a double layer weave with binders and stuffers (closed tubular with stuffer). Other weaving configurations have proven successful in meeting and or exceeding the break load requirements. Webbing may be woven on a shuttle or needle loom When needle loom construction is utilized the filling yarn shall traverse the full width of the webbing and shall be held at the knitted edge by a catch cord interlacing with filling yarn. Webbing may be woven with the system 3 catch cord on the latch needle edge or the system 5 catch and lock cord on the latch needle edge. Treated and untreated nylon and polyester webbing, used to fabricate synthetic slings, per class 5 and class 7 rated capacity charts as shown in WSTDA-WS-1, may contain red yarns woven into the core of the webbing to serve only as one of many aids in determining whether and when a sling should be removed from service. Class 5 nylon and polyester sling webbing, treated or untreated, shall have a minimum breaking strength of 6800 pounds per inch of width ( kilograms per millimeter of width). Class 7 nylon and polyester sling webbing, treated or untreated, shall have a minimum breaking strength of 9800 pounds per inch of width (175 kilograms per millimeter of width). Both webbing classes and types may be available in natural or dyed, and in treated or untreated types Identification Marker for Fiber Type Identification marker shall be a color sealed or dyed yarn Location of Marker for Fiber Type Marker shall be located in the center of the webbing on at least one face. 3

8 Codes: Fiber Color Code Nylon No Marker Polyester Blue Marker Identification Marker for Synthetic Sling Webbing Manufacturer The webbing manufacturer identification markers shall be color sealed or dyed yarns. Location of Marker for Synthetic Sling Webbing Manufacturer All double and multiple layer weaves shall be identified for manufacturer's color code in accordance with the following options: a. Color code markers located in the binder. b. Color code markers located between the surface plies Codes For color coding questions or application for color assignment contact WSTDA. SECTION 2.4 TREATMENTS Synthetic sling webbing may be treated with suitable materials that will impart desirable characteristics such as: a. Abrasion resistance b. Sealing to prevent penetration of foreign particles and matter c. Increased coefficient of friction d. Ultraviolet light resistance CHAPTER 3.0 STANDARD PROCEDURES FOR TESTING SYNTHETIC SLING WEBBING SECTION 3.1 PURPOSE This chapter provides standard procedures for testing synthetic sling webbing used for nylon and polyester class 5 and class 7 web slings. SECTION 3.2 TYPES OF TESTS Destructive Breaking Strength A test of the webbing for the purpose of verifying the breaking strength. The webbing shall be tested in a straight line pull until broken Abrasion A test of the webbing to determine resistance to abrasion Elongation A test of the webbing to determine the elongation of the webbing under load Other If additional test(s) are required, they shall be specified by the purchaser. SECTION 3.3 TEST PROCEDURES Webbing shall be tested for breaking strength and elongation in accordance with the WSTDA- TM-1 Strength & Elongation Recommended Test Method for Sling & Tie Down Webbing. Webbing shall be abrasion tested in accordance with ASTM D 6770 Standard Test Method for Abrasion Resistance of Textile Webbing (Hex Bar Method) Test specimens shall be from each actual production run Test results shall be kept on file by the webbing manufacturer The webbing manufacturer or an independent testing laboratory shall perform the testing of synthetic webbing for slings. 4

9 SECTION 3.4 CERTIFICATION When certification is required, the company performing the testing shall issue a certification describing the webbing type, part or model number, date, and results of the tests performed. SECTION 4.1 PURPOSE CHAPTER 4.0 RECOMMENDED OPERATING PRACTICES The purpose of this chapter is to provide guidelines for the care, use and inspection of synthetic webbing for slings. SECTION 4.2 ENVIRONMENTAL CONSIDERATIONS Webbing should be stored in a cool, dry and dark location Environments in which synthetic webbing is continuously exposed to ultraviolet light can affect the strength in varying degrees, ranging from slight to total degradation Polyester and nylon webbing shall not be used at temperatures in excess of 194 degrees F (90 degrees C) or below minus 40 degrees F (-40 degrees C). SECTION 4.3 INSPECTION Webbing should be inspected by the sling manufacturer for the following conditions: a. Width b. Thickness c. Manufacturing Flaws d. Fiber Type e. Conformance to sling manufacturers requirements SECTION 4.4 INSPECTION RECORDS Sling manufacturers should maintain material inspection records. SECTION 4.5 REPAIR OF WEBBING No repairs of webbing shall be permitted. This Recommended Standard Specification has been formulated to assist manufacturers of webbing and web slings to serve as a guide to the industry involved in the manufacture of synthetic sling webbing, and to serve as a guide to governmental and other regulatory bodies responsible for the selection of webbing used in synthetic slings. The existence of this recommended standard specification does not, however, prevent members of the Web Sling & Tie Down Association, Inc. and other manufacturers from manufacturing or selling products beyond the scope of this recommended standard specification. 5

10 OTHER WEB SLING & TIE DOWN ASSOCIATION PUBLICATIONS Recommended Standard Specifications: Recommended Standard Specifications: Printed Books Synthetic Web Slings (Spanish) Synthetic Web Slings Synthetic Polyester Roundslings High Performance Yarn (HPY) Roundslings Webbing for Synthetic Web Slings Sewing Threads for Slings & Tie Downs Synthetic Web Tie Downs Winches Used With Web Tie Downs Synthetic Webbing Used for Tie Downs Load Binders Used with Chain Tie Downs All Standards In A Three-Ring Binder WSTDA-WS-1 WSTDA-WS-1S WSTDA-RS-1 WSTDA-RS-1HP WSTDA-WB-1 WSTDA-TH-1 WSTDA-T-1 WSTDA-T-3 WSTDA-T-4 WSTDA-T-6 WSTDA-ASB PDF Files On CD All Standards CD - (All Standards on CD) Recommended Test Methods: Strength & Elongation Test Method for Sling & Tie Down Webbing WSTDA-ASCD WSTDA-TM-1 Operating & Inspection Manuals Synthetic Web Slings (Spanish) Synthetic Web Slings Synthetic Polyester Roundslings Synthetic Web Tie Downs WSTDA-WS-2 WSTDA-WS-2S WSTDA-RS-2 WSTDA-T-2 Synthetic Web Slings Synthetic Polyester Roundslings WSTDA-WS-PS-2 WSTDA-RS-2-PS (pocket sized) (pocket sized) Illustrated Wall Chart Inspection of Web Slings & Roundslings WSTDA-WSWC-1 UV Degradation Reports Summary Report UV Degradation UV Degradation Mini Manual UV Degradation Report WSTDA-UV-Sling-2003 WSTDA-UV-MM-2005 WSTDA-UVDR-1981 (Revised 2005) Training CD-Rom North America Cargo Securement Standard WSTDA-CD-TP-2003 Warning Labels Safety Bulletins Web Slings Tie Downs Roundslings WSWT-1 TDWT-1 RSWT-1 Web Slings Roundslings Tie Downs WSSB-1 RSSB-1 TDSB-1 All Warning Labels and Safety Bulletins are available in three languages; English, Spanish and French For ordering information and prices, contact the association office or visit our website: Web Sling & Tie Down Association, Inc. 9 Newport Drive, Suite 200 Forest Hill, Maryland Phone (443) Fax (443) wstda@stringfellowgroup.net Web Site: